The invention relates to an apparatus for the precise dispensing of particulate material either at a uniform flow rate or in repetitive accurately measured discrete quantities or batches. Such apparatus finds application where it is necessary to provide accurately measured particulate material for subsequent mixing, treatment, packaging, or the like. The apparatus includes the housing having a hopper in the upper portion thereof for storage of the particulate material. A discharge from the hopper includes a fixed orifice transfer tube extended through the floor of the hopper. An endless conveyor belt is provided to carry particulate material discharged from the hopper to a dispensing location. A metering tube is telescopically engaged at its upper end with the lower portion of the discharge spout of the transfer tube. The lower end of the metering tube is in close proximity to the upper forward run of the conveyor belt. The elevation of the lower end of the metering tube above the forward run of the conveyor belt is adjustable. The spacing between the lower end of the metering tube and the upper surface of the forward run of the conveyor belt is a first determinative factor of the amount or rate of particulate material discharged from the hopper. The speed of the conveyor belt is precisely regulated by an electric motor. The speed of the conveyor belt as the forward run moves under the lower end of the transfer tube is a second determinative factor of the amount or rate of particulate material discharged from the hopper. The conveyor belt delivers particulate material deposited upon it to an outlet discharge tube.
The apparatus can provide a uniform flow of particulate material for mixing, treatment or packaging or the like. Alternatively, the apparatus can provide a series of repetitive, accurately measured discrete quantities or batches of material. This is accomplished by precise control of the duration of operation of the electric motor to run the conveyor belt. In a set-up mode, a sample run is made where a desired amount of particulate material is discharged from the hopper and delivered to the dispensing location. The electric impulses directed to the electric motor during the set-up mode run are carefully measured and this information is set into a comparator. Thereafter, a control unit operates the electric motor to duplicate performance during the set-up mode whereby during each successive run there is delivered the same amount of particulate matter as during the set-up mode.